1. Field
One or more exemplary embodiments of the invention relate a thin film transistor (“TFT”) array substrate and an organic light emitting display apparatus including the TFT array.
2. Description of the Related Art
Recently, an organic light emitting display apparatus is widely used as a display apparatus for displaying an image.
The organic light emitting display apparatus typically includes a pixel circuit connected to a plurality of signal lines disposed on a substrate, and an organic light emitting diode (“OLED”) connected to the pixel circuit.
Since an active layer that defines a source, a drain and a channel of an amorphous silicon thin film transistor (“a-Si TFT”) used in the pixel circuit includes amorphous silicon, the a-Si TFT has low electron mobility lower than or equal to 1 square centimeter per volt second (cm2/Vs). Accordingly, recently, the a-Si TFT is being replaced by a polycrystalline silicon TFT (“poly-Si TFT”). The poly-Si TFT has high electron mobility and excellent stability to light irradiation compared to the a-Si TFT. Thus, the poly-Si TFT may be effectively used as an active layer of a driving and/or switching TFT of the organic light emitting display apparatus.
Poly-Si may be manufactured via any one of various methods. Among the various methods, large panel crystallization may be performed using an excimer laser annealing (“ELA”) method.